from waterworld to wasteland fluids or vasopressors in...
TRANSCRIPT
Walid Habre, MD, PhD Paediatric Anaesthesia Unit
Geneva University Childrens Hospital
From waterworld to wasteland Fluids or vasopressors
in children
Is it a controversial issue or an evidence-based consideration ?
Goal-oriented approach
Objectives of the talk: 1. Define the Goal-Oriented approach
2. Limitation of the classical approach based primarily on Fluids
3. The methods that can help us deciding what kind of intervention and which children should benefit?
4. Provide some recommendations and strategies for perioperative management in children
Goal-Oriented approach
Meet the requirements and effectiveness of individual treatment
Blood Pressure
Cardiac output
Intravascular volume
Manipulating hemodynamics to optimize oxygen transport
• Child (African American) 22 months, 10 kgs scheduled for difficult hypospadias repair.
(potential buccal mucosal graft)
Inhalation induction with sevoflurane, iv access and administration of fentanyl 1 mcg/kg and atracurium 0.5 mg/kg
Pressure dropped from 105/70 to
65/30
HR increased to 170/min
Classical : lowest acceptable SBP: 2 x age in yrs + 70
Age Lowest acceptable SBP
Term neonates < 28 days 60
Infants 1 – 12 months 70
Children 1-10 yrs 2 x age (yrs) + 70
Children > 10 yrs 90
200 ml NS and 2.5 mg ephedrine
Ultimate goal of Goal-Oriented approach
ì oxygen delivery index
Improve outcome in high risk patients
Combination of intravenous fluids & inotropes
Goal directed therapy
Classical approach:
èFluids to target the following:
- Preoperative fluid deficit
- Maintenance fluid: 4-2-1 rule
- Crystalloid fluids replacement
- Third space fluid loss: 5ml/kg/hr
Crystalloids Colloids
Estimated blood loss: x 3 x 1
?
?
Match the increased oxygen demand by flow-based haemodynamic monitoring and therapeutic interventions to achieve a predetermined haemodynamic endpoint.
Goal-Oriented approach
Current values for hypotension are not evidence-based and may need to be adjusted for patient
height and for clinical condition.
Hacque IU et al. Pediatr Crit Care Med. 2007; 8:138-44.
SBP (5th percentile at 50th height percentile) =
2 x age in years + 65
MAP (5th percentile at 50th height percentile) =
1.5 x age in years + 40
MAP (50th percentile at 50th height percentile) =
1.5 x age in years + 55: in sick children
New approach:
èFluids and vasopressors to target the following:
- Preoperative fluid deficit: clear fluids 2h before - Maintenance fluid: 4-2-1 rule
- Crystalloid or Colloids fluids replacement: 1 to 1 - Third space fluid loss: not replaced - Inotropes/vasopressors
Aim of intraoperative fluids: avoidance of both hypo- and hypervolaemia to prevent adverse outcomes
Doherty M et al. Br. J. Anaesth. 2012;bja.aes171
Effects of fluid overload
• Increase peripheral perfusion/oxygen supply
• Increase intraoperative diuresis and avoid postoperative renal failure
• Fluid homeostasis decreases PONV
• Decrease in pulmonary function with risk for hypoxaemia and respiratory complications
• Promote extravascular fluid extravasation with oedema
• May impair oxygen diffusion and decrease tissue oxygen tension
• May have negative implications for wound healing
Advantages Inconvenients
Effect of fluid load on lung function
Promote lung interstitial fluid accumulation
Crystalloids and Colloids impair Respiratory compliance
Decrease compliance Impair gas exchange
Hypoxaemia
ì intravenous fluid administration è ì postop complications
Effect of fluid load on the renal function
Surgery-Stress
ACTH
Cortisol
ADH
Renin î Diuresis î Na excretion
Aldosterone
ì water absorption
Fluid load
ì GFR
ì Extracellular Fluid volume
î GFR
Effect of fluid load on gastrointestinal function
Crystalloids seem to predispose to higher incidence of intestinal Oedema than colloids
Effects of perioperative fluid therapy on the Starling myocardial performance curve
Holte K et al. Br. J. Anaesth. 2002;89:622-632
Aim of fluid challenge
ì stroke volume (SV)
ì cardiac output (CO)
ì oxygen delivery
Relationship between cardiac output and fluid administration.
Holte K et al. Br. J. Anaesth. 2002;89:622-632
Cannesson M. J CardioThoracic Vasc Anesth 2010; 24: 487-497
Frank-Starling relationship between ventricular preload and ventricular stroke volume
Cannesson M. J CardioThoracic Vasc Anesth 2010; 24: 487-497
Frank-Starling relationship with associated respiratory variations in the arterial pressure waveform signal
The use of heart-lung interactions during mechanical ventilation to assess fluid responsiveness
derived from analysis of arterial waveform
Stroke volume variation (SVV)
derived from pulse contour analysis
Systolic pressure variation (SPV) Pulse pressure variation (PPV)
PPV % = 100 x (PPmax –PPmin) / ((PPmax + PPmin) / 2)
RCT’s with SVV or PPV demonstrating improve outcome
Michard F. Crit Care. 2014; 18: 413
Typical algorithm for oesophageal Doppler-guided fluid management with characteristic velocity waveform
obtained from the descending aorta
Doherty M et al. J Br. J. Anaesth. 2012;bja.aes171
The haemodynamic profile integrates ABF, mean arterial pressure (MAP), heart rate (HR), and calculates a stroke volume in the descending aorta: SVa (ml) = ABF/HR
Predicting fluid responsiveness in children: is it realistic ?
• The Starling curve: does it exist in neonates?
• Dynamic variables derived form heart-lung interaction: are they good predictors?
• Are classical static variables reliable?
Heng G et al. Anesth Analg 2013; 117: 1380-1392
Accuracy is measured by the area under the ROC curve
An area of 1 represents a perfect predictor test An area of .5 represents a worthless test
Receiver operating curves (ROCs) of cardiac index to discriminate
responders and nonresponders to volume expansion.
Area under the curve 0.71 ± 0.084 (95% CI 0.546-0.874)
The role of passive leg raising to predict fluid responsiveness in pediatric intensive care unit patients
Vimaladewi L et al. Ped Crit Care Med 2012; 13(3):e155-e160,
Comparison of the areas under the ROC curve for static variables:
More the ROC tend to 1 Excellent predictor
Comparison of the areas under the ROC curve for dynamic variables
Aortic Peak Flow Velocity
Which fluid to use in children ?
Body fluid compartments with main ion distribution
Doherty M , and Buggy D J Br. J. Anaesth. 2012;bja.aes171
Balanced crystalloids are closer to plasma content
Myburgh JA et al. N Engl J Med 2013;369:1243-1251.
Children with severe febrile illness and impaired perfusion: 20 to 40 ml/kg of 5% albumin or 0.9% saline or no bolus
Maitland K et al. N Engl J Med 2011;364:2483-2495.
Principal cause of death: cardiovascular collapse
rather than fluid overload or neurologic causes
Adverse interaction between bolus fluid resuscitation and
compensatory neurohormonal responses ?
FEAST study
Relationship between hydroxyethyl starch volume and probability of acute kidney injury (AKI)
Kashy, Babak K et al. 2014; Anesthesiology 121(4):730-739
Which vasopressor to use in children ?
PALS algorithm: can we apply it in the perioperative period?
Push 20 ml/kg isotonic saline or colloid boluses (Up to 60ml/kg in sepsis) Correct hypoglycemia and hypocalcemia
Begin Dopamine therapy
Fluid refractory-dopamine resistant shock
Cold shock Warm shock
Titrate Epinephrine Titrate Norepinephrine
Dopamine or norepinephrine as first-line shock: SOAP-II trial
De Backer D et al. N Engl J Med 2010;362:779-789.
Concensus based recommendations
Peripheral line
DOPAMINE 3 mcg/kg/min
β: ì HR & contractility: ì CO & SBP δ1: vasodilation of capillary beds increases renal perfusion
Central line
NOREPINEPHRINE 0.01 mcg/kg/min
Titrate up to 7 mcg/kg/min Get a central venous line and an arterial line
α1 : V-C and ì SVR β1 : some: ì inotropisme
Other inotropes and/or vasopressors ?
Adrenaline 0.01 mcg/kg/min
β1 & α1
ìHR, SV, CO ì SVR
Dobutamine 2-10 mcg/kg/min
β1 & β2
î SVR ìHR, CO
Tachyarrhythmia and ì myocardial oxygen consumption
To consider in case of cardiac failure
Optimisation of the depth of anaesthesia and interventions to rectify changes in cerebral oxygen desaturation
Balard C. et al. PLoS One. 2012; 7(6): e37410.
BIS between 40-60 Monitor rSO2
Preoperatively: - Watch up the NPO: clear fluids up to 2 hrs before - If Vomiting or gastro-intestinal losses: give NaCl - Post-induction hypotension: is not related to decrease volume and thus, very often responses to vasopressors
Intraoperatively:
- HR, BP, CVP, urine output, Cap filling: lack sensitivity - Individualize goal-directed fluid therapy - Use indices derived from Frank-Starling curve - Use albumin for early resuscitation - Use balanced fluids close to plasma content - Avoid NaCl to decrease risk for Hyperchloremia
Postoperative period:
- Evaluate status : hypovolemia and/or tissue hypoperfusion - Control unexpected blood or fluid loss - Avoid hyperhydration (SIADH) - Switch to oral intake rather than intravenous
Goal-Oriented approach
Blood Pressure
Cardiac output
Intravascular volume
ìoxygen delivery index optimize oxygen transport
Improve outcome in high risk patients
O2 Hb